pretty apprehensive..... during backing up of my 4S to iTunes & iCloud, I see that none of my contacts are on iCloud.
I'm proceeding with caution, for sure! until I confirm my contacts are backed up, I'm not jailbreaking

i did my wifes and all is runnnig smooth ,but it was a little easier since she had never been jailbroke before and she was already updated to ios6 , so i spent last night adding some customizations from cydia. cydia servers or sources got hammered hard yesterday .so alot of people where complaining about errors. but all seems to be working today. i have had no issues with my wifes phone ,i am still scared to update my phone.also . i just did a full restore on my kids ipod which was jailed , so i am waiting for him to come home and see how his restore from icloud works out . if no issues found i may tackle my phone next week .

as for the jailbreak itself ,no glitches with the phone at all. and this jailbreak software is so easy
to do i can see everybody eventually trying it . just plug in the phone to computer and hit run .
i think it promps you once to unlock your device and tap the app icon once and then it finishes the jailbreak, then after all is done run cydia and it will update , i did see a update for the jailbreak also on cydia .or something from the jailbreak crew on cydia that needed updating on the phone . this is the easist jailbreak user friendly exe .ever.

I've been downloading 6.1.1 through iTunes for last 3 hours and it says there's 5 left

edit:
aborted that downloaded last night, reset phone to new phone, took update, synced phone with iCloud backups, all was good, applied evasi0n's Jailbreak, and good to go.... just gotta add the vital jailbroken apps back for now, then the not so vital ones later
my primary purpose to go to iOS 6.0+ was for the GPS maps feature, or I'd have stayed at 5.1.1